Tetrandrine inhibits deregulated cell cycle in pancreatic cancer cells: Differential regulation of p21Cip1/Waf1, p27Kip1 and cyclin D1

Treatment of PaCa cells with TET results in increased protein levels of p21Cip1/Waf1 and decreased protein level of cyclin D1. Changes in these cell cycle regulatory proteins directly inhibit activities of CDK4/6 resulting in decreased phosphorylation of Rb and limiting expression of Skp2. Decreased Skp2 ensures increased stability of p27Kip1 further increasing the levels of p27Kip1. All these changes put a break on deregulated cell cycle at G1/S boundary.160